Rusty's not very quiet cuda progress

[Dr.Jass]

OK, after more than two hours of modifying the factory 1974 service manual diagram for wire colors and gauges, this is as clear as the 1974 E-body bulkhead disconnect is ever going to be. All of the information is from the 1974 FSM, with the '73 diagram used as a cross-reference for changes.

I included the AWG because there are wires of the same color with completely different circuits and functions, which are only discernible by their size. The black wire for the alternator is massive compared to those for the back-up lamps and washer pump, and those two are also different sizes (18 and 20 gauge, respectively). Remember: A smaller number means a bigger wire.

Cavities I marked with a "√" by them have a completely different function between 1973 and 1974. That's a reminder to check what wires you've got in those positions on your engine harness once it arrives. All of the other positions have the same function, wire size and color codes between 1973 and 1974. If you have something different in one of the unchecked positions, you've got some diagnostic work or other-year FSM research in your future.




The FSM wire color legend:




First and foremost, the AC clutch and blower motor wires do not go to the bulkhead connector according to the 1974 factory manual. Those two wires pass through a rubber grommet in the firewall. I added this to the diagram, with the "wires" pointing to the grommet. The grommet is in approximately the right position in relation to the bulkhead connector.

There are no "early/late" or "with seatbelt interlock/without seatbelt interlock" wiring diagrams that I'm able to find. The 1974 service manual shows every car as if it were built with the interlock system, regardless of build date or body style. I don't see any notes to refer to the 1973 manual for cars built prior to a specific date anywhere in the service manual. Even the basic starter-motor diagnostic and service procedures at the very beginning of the electrical section describe the seat-belt interlock as the very-first part in the electrical flow. There are also no "early/late" wiring harnesses shown in the factory parts book.

Next in order of importance: This diagram shows the function, color coding, and wire sizing on the engine side of the bulkhead only, meaning the wires in the engine and forward lamp harnesses. Colors on the interior side of the bulkhead don't necessarily correspond. Long story short: This diagram is useless on the interior wiring harness.
The 1973 bulkhead diagram shows color changes passing through the bulkhead connector (look at the picture you took in post #3181), but the 1974 FSM diagram does not. To know how the wires on the interior side should appear, one needs to reference specific individual diagrams for each of the four plugs on the bulkhead. Those show the wire colors and gauges on both sides of the disconnect. You cannot use a 1973 manual to do that; it must be the '74 version.

Could there be a mystery wiring diagram out there, or some reference to use 1973 wiring diagrams up to a certain date that I'm not able to find? Absolutely. My assumptions here are based solely on the factory literature I'm able to find, including an original (non-reproduction) factory service manual.

Once again, the car's 50 years old. Nobody involved now has any idea what prior owners did to the car. Based on the mass of yellow engine-compartment wiring, it certainly looks like it had the interlock. On the other hand, your handwritten notes on where the wires were located seems to indicate that the AC clutch and AC (blower) motor wiring went through the bulkhead, a la 1973. Cavity 4 is no big deal, since you haven't got a tach. Cavities 9 and 19 are easily-enough swapped if need be. It's what's wired to the interior side of Cavity 20 that makes me wonder.

I've got nothing further until you have your new wiring harness in-hand and we know what's on the other side of that bulkhead. Break out the digital multimeter; you're gonna need it for continuity testing. I wouldn't even consider connecting a battery until the wiring's 100% sorted.

 

[RUSTY Cuda]

Hey Jass, this is above & beyond the call of duty, I thank you a TON for all your help.
Once the harness gets here, I'll check out their colors & see what's off, or hopefully ON!

I'm thinking of tearing off all the covers on the old harness & doing some basic tracing there, I just can't figure how they ran I big wire to around the center of that secondary large connector & anything after it worked?


Just printed that all out , it will be with me when I tear into the old harness!

 

[RUSTY Cuda]

Wow what a mess, I peeled back most of the tape on the engine harness, I honestly don't know how anything worked on this car!
Off the connector that plugs into the bulkhead looks like they separated out the alternator field wires & a couple of sensor wires...........
The main alternator wire (I think) goes directly to the secondary connector & it's the only wire going into it! Now the secondary is beyond belief, a couple of the wires just loop around from one side to the other BUT into different ports! one comes off both sides again different ports & then is tied together& joined with other wires!
I guess you guys know this is how it should look, well except for the fried alrernator wire connection that was bypassed!

 

[RUSTY Cuda]

Now this is the big kicker, the one that plugs into the bulkhead, NONE of the colors match the 73 or 74 book!
Now the secondary connector MATCHES all the right wires/colors!!!!!!!!!!!!

 

[RUSTY Cuda]

There are no breaks for this old man, Exhaust system came today in the middle of a down pour, that later flooded my property with a 14 or so inch river flowing through it.
We got it in the front hall & about 2 1/2 hours ago I went out to haul them to the garage, open the garage to get the hand truck & what a disaster, couple of boxes on the lower shelf with parts got wet, a giant box I had up in the air got knocked over in it was all my interior panels & parts.
so after emptying all the boxes cleaning all the parts I finally hauled the boxes in the garage, one on top was squished pretty good, didn't think any exhaust parts could get hurt but figured I'd better check anyway, to my surprise it was the sail panels (not damaged) & the harness.
Now mind you I'm not exactly in a good mood, but I had to check the harness, well I should have left it till tomorrow, I think I got the wrong one after triple checking the part #

I didn't actually check but it looks like all the colors match the 74 book & it has those extra yellow/Y w/blk* wires.

I'm fried, so I'll start looking at year one site & check my #'s tomorrow which I hope will be a better day!

How was your day!

 

[Dr.Jass]

That 4-wire plug furthest to the right (Y, Y, DBL, BK wires) is for the interlock bypass switch. The label says "DODGE & PLYMOUTH E-BODY, before 10/12/73" (emphasis added).

The only differences in the interlock system of which I'm aware was the engine-compartment override switch, which changed twice during model-year 1974 production. Neither of those dates is in October. More importantly, the first part number shows that the early-production interlock switch was used well into September, which is almost certainly earlier than your car. These are hard parts to find, never mind photos thereof, but the only difference between 3746724 and 3746910 may be the writing on them (highlighted).



This aligns with the information in the service manual indicating that all 1974 models had the interlock system regardless of production date. Technically, it's probably the right harness for a car built prior to 10/12 (assuming they have the cutoff date right), but your sequence number suggests the car was likely built after that. It also shows that Herb's has their information wrong. Year One got all the factory blueprints when they acquired the connector molds in the early '90s, so their information is based on those prints. Sadly, this is not information to which their customer-service or sales staff has access. Based on my understanding of the manufacturing world, I'd say the new blueprint was approved 10/12/73 but the change wasn't implemented until 11/16. That change, I believe, involved moving the interlock switch from the inner fender to the firewall, but I can't verify that.

This is precisely why I wanted you to wait until we knew exactly what was going on in your car prior to ordering a harness. Don't order anything else, and don't return that harness yet. Year One has a very customer-friendly return policy so they'd still help you a year later, if it took that long (but it won't).

No more assumptions! What you need to do before you make any returns or order more parts is some basic continuity testing with a digital multimeter, preferably one that beeps when performing said test (I've never had one that didn't, even my $8 unit). Technically it could be done by wire color inside the firewall, but my guess is that doing so would ultimately be harder.

Work on something else for the moment while I figure out the easiest, most direct way to test your bulkhead connector so you get a drop-in harness, or at least the closest thing available. You might have to pull the cluster (not the whole dash) because you'll need access to the back of the wiper switch.

DON'T DO ANYTHING WIRING-RELATED until I post the test procedure, capiche? Let's figure out once and for all exactly what you've got, then we can worry about which harness to get. Fair?

 

[Dr.Jass]

OK, here's how you need to test your bulkhead. Use any of the bulkhead diagrams I've posted thus far, since the positions are always numbered the same. Completely ignore any references to each cavity's function or wiring in the diagram; we're only worried about its numeric position.

Thinking further, I don't think you'll need to remove the whole cluster to access the back of the wiper switch. I think you can remove the light bar and the light/wiper switch panel will come out by itself. I could be wrong; I haven't disassembled one in 35 years.

Preferably, you'll have someone to help that can hold one multimeter (DMM) probe in the bulkhead cavity you're testing. This is preferred, since your helper can listen for continuity while your head is under the dash. You can do it alone if you must, but that involves gently placing the probe in the cavity being tested so it'll stay there while you probe the other side. Do not force or jam anything or you may damage the terminal. If you have to do it alone, place the multimeter as close to the interior as possible so A) you have enough length on the other probe, and B) you can hear the multimeter beeping. If you can lay it on the dash pad or fender, that's ideal.

No engine-side wiring can be connected to the bulkhead during this procedure. The bulkhead must be bare on the engine side of the firewall. Unplug anything that's currently installed.

Set the multimeter to check continuity. If you're borrowing the multimeter, have the owner show you how to set it so that holding the two probes together results in a continuous beep. You can use either probe on either end; there's no polarity in a continuity test.

If it seems like I'm over-explaining this, someone less experienced might be reading this five years hence and have no idea how to use a DMM. The less I have to explain in the future, the better.

Since none of the other cavities changed function between 1973 and 1974, we're only really concerned with four of them: 4, 9, 19, and 20.

On with the procedure!

Step 1: Check Cavity 9.
Put one test probe in Cavity 9 on the engine-compartment side. Take the other probe and find the ignition-switch connector at the steering column (8 pins inline, rectangular, four flat sides). If it's not plugged in yet, use the body side, not the side that goes into the column. Touch your probe to the large yellow wire (12ga Y). Listen for continuity (the multimeter should start beeping continuously).

Step 2: Cavity 19.
Move your engine-compartment probe to Cavity 19. Use the other probe at the 18-gauge brown (BR) wire at the back of the wiper switch (the terminal is marked W on the switch, there is NO tracer on wire). Does it beep?

If you had continuity (beeps) in both Steps 1 & 2, you can skip to Step 5. If you did not, continue to Step 3.

Step 3: Check Cavity 9 again, except this time on the interior side you want to check it against the 18ga BR (no tracer) wire at terminal W on the wiper switch. Is there continuity now?

Step 4: Check Cavity 19 again, but now you want to check it at the 12ga Y wire on the ignition-switch harness (where you checked Cavity 9 in Step 1). Does this get you a beep?

Step 5: Cavity 4
Put your probe in Cavity 4 on the firewall. Take your other probe and touch it to the dark green (DGN) wire (either one) at the blower-motor resistor connector. Does it beep?

Step 6: Cavity 20
With one probe in firewall Cavity 20, touch the other to the dark blue (DBL) wire that connects to the HVAC controls (should be at top center). Have we a beep?

Respond with results. Keep it simple, i.e. "Step 1, beep. Step 2, no beep" and so forth.

 

[RUSTY Cuda]

I think before I return the harness I will hunt down a complete 74 service manual or at least all the wiring diagrams, & try & figure out what the heck I have under the dash?

 

[RUSTY Cuda]

OK I typed above before reading your response, I will see if I can get those test's done & give you a definitive answer, my 73 book might suffice if that's what I have under there?
So by me using herbs pics to determine which to order I got them backwards, or do they both have the yellow lock out wires????????

I do have a couple of testers, beeping I don't remember, tomorrows family stuff, so I hope to do it monday?

 

[RUSTY Cuda]

So after a couple more hours of cleaning up water damage I took a look at the exhaust system, headers are perty! I did spring for the ceramic coated.
Big box a goodies!
I had them weld the tips on, the hanging bar is also welded on.
I knew I was missing the brackets under the seat pan so I ordered those (up on the cardboard)& I got lucky out back, the other system had a home made hanger, but they left the original brackets on the car which I cleaned up & re-installed.
So they say they will clear my sway bar, but there is a note in there you have to bend a 3 pcs kickdown linkage, mine is the one rod from carb to tranny hope that is fine??? that worries me!

 

[74DartSport]

Can I loan you these?

 

[Dr.Jass]

OK I typed above before reading your response, I will see if I can get those test's done & give you a definitive answer, my 73 book might suffice if that's what I have under there?

Whether you need 1974 manuals or wiring diagrams depends entirely on the results of the test I posted. If it comes to that, I have the 1974 wiring diagrams. I can e-mail them to you, but I'm not going to do that at the moment. It will only serve to confuse things. Do the test.

So by me using herbs pics to determine which to order I got them backwards, or do they both have the yellow lock out wires?

Herb's information is just plain wrong. All 1974 harnesses will have the seatbelt interlock wiring, because all 1974 cars had the interlock. Re-read the inormation in post #3,206 above about the interlock switch, which had three different part numbers based on date.

I do have a couple of testers, beeping I don't remember, tomorrows family stuff, so I hope to do it monday?

Even my cheapest junk DMM has a confirmation beep. If nothing else, post a picture of the one you're going to use and I can probably figure it out or show you how to set it for the beep.

I have to work Monday, so I'll check in but responding might take a little while. Be patient after posting results.

 

[Dr.Jass]

& I got lucky out back, the other system had a home made hanger, but they left the original brackets on the car which I cleaned up & re-installed.

Go ahead and unbolt those now before they cause confusion later. They're absolutely not E-body tailpipe hangers nor even close to 'em. They're also in the completely-wrong location. Regardless of what the prior owner had bodged into place for an exhaust system, those have no place on your 'Cuda. Put them in your box of spare parts completely unrelated to this car. Or, if you prefer, toss 'em.

Look at your instructions. Since the TTi system does not put the mufflers in their original location on either side of the fuel tank, their tailpipes have that goofy-looking hanger tab welded to 'em. I'd find it very surprising if they didn't include tailpipe hangers. I'll bet they did. In fact, I think they're circled in green here:




The factory E-body muffers were located behind the axle, on either side of the fuel tank. This was the case in all years, in all applications. This is a factory-style muffler and exhaust tip for a Challenger:



See how high the OE hanger tab is, and how it's bolted to the muffler rather than the tailpipes?

The tailpipe (tip) hangers bolt directly through the trunk floor, using brackets that drop through existing holes in the trunk. The same brackets also support the muffler heat shields (which you don't have, and don't need with your new exhaust). The hangers are circled in blue on the diagram, while the brackets that drop through the trunk are circled in red:




This is what one looks like up-close. The flat bracket's studs drop through the trunk floor (the bracket itself is visible inside the trunk) and hang down to secure the hanger:




The holes in the trunk where the OE exhaust hangers mount are circled in green, shown on your very own car:



As you can see, that's about a country mile from the frame rail. I would bet one American dollar that the parts I circled in green in your box o' exhaust parts are simply TTi versions of the factory-style hangers, and install in the same location in the trunk floor. Read the instructions that (hopefully) came with the exhaust. What I don't see are the flat brackets, so maybe they just use nuts and bolts through the factory holes. If that's the case, make sure to put washers between the bolt head and the trunk floor.

So they say they will clear my sway bar, but there is a note in there you have to bend a 3 pcs kickdown linkage, mine is the one rod from carb to tranny hope that is fine??? that worries me!

If they didn't mention the 1-piece setup, don't worry about it. The 3-piece articulated linkage has a lower pivot and shaft that can interfere with the header and/or exhaust pipe on the driver's side. Those parts aren't present on the 1-piece setup you have.

 

[RUSTY Cuda]

OK, wiring on hold till I do the test!

I thought the exhaust in the back were resonators, oh well how much I know!

Not that it matters but I do have the heat shields, the pic of the mystery hanger shows it (in black) I was waiting to cap off that fuel return line before I put the other one on.

I do have the top half of the rear brackets in the trunk, with studs that stick through, I do not have the lower half, I'll check that box maybe I'll get lucky?

Those pieces on the rail sure look factory, there's a bolt hole & a positioning tab & corresponding holes in the rail?

 

[Dr.Jass]

I thought the exhaust in the back were resonators, oh well how much I know!

The resonators were ahead of the rear axles, where your mufflers will be with the TTi setup. The only E-body that had mufflers ahead of the rear axle were the 1970 T/A and AAR, and resonators were only originally used on HP cars. The complete setup looks like this, other than the home-made resonator hangers:



If you look closely, you can see the over-axle pipe is part of the muffler. There's no joint there. The resonator nipples are center in, center out, where mufflers on other models are offset on the inlet. Non-HP cars no resonators and the mufflers were still mounted behind the axle.

I do have the top half of the rear brackets in the trunk, with studs that stick through, I do not have the lower half, I'll check that box maybe I'll get lucky?

Like I said, I'm pretty sure the parts that I circled in green in your TTi box are the tailpipe hangers. They should fit the OE trunk plates.

Those pieces on the rail sure look factory, there's a bolt hole & a positioning tab & corresponding holes in the rail?

I don't know what function they'd serve. They won't fit any factory E-body exhaust system. There may be some other Chrysler with a similar hole arrrangement in the frame, but they're definitely not Barracuda/Challenger parts.

 

[RUSTY Cuda]

Got home a little while ago, had to go out & at least check the brackets & bring in my meters for batteries, sitting around since I retired!
Bottom halfs are there & I have the top half in the car!


I have a meter, the fluke still works & there is a bleep, or should I say peep, not very loud!
I dug out dad's simpson, which I never really figured out anyway, but the AA battery rotted out the lower connection in there. I would not have had that other battery anyway, one less thing hanging around, she's been canned!

I think the first one I'll try is the starter wire, that is just hanging under there, then see what the access to the other ones looks like!
I think with the door open there is enough wire to lay the meter on the dash, maybe even on the floor next to my aching body!
I'm pretty sure I can get to the wire on the heater control from the back, the others I have to look into, I hope I don't have to take it (the dash) apart!

 

[RUSTY Cuda]

View attachment 26173
Can I loan you these?

Let me see what the test results are, I may take you up on that.
You were from moonachie Right?
Still local, if you get bored & want to hang out shoot me a line we can arrange a mopar day!

 

[74DartSport]

Boonton actually. If you need them let me know.

 

[68R/T]

RUSTY Cuda said:
"Those pieces on the rail sure look factory, there's a bolt hole & a positioning tab & corresponding holes in the rail?"

Those are for "B" bodies with dual exhaust, Coronet R/T's, Roadrunners, GTX's, Chargers. They were used with these type of tips. (Of which I have 2 cars)

 

[RUSTY Cuda]

OK, you need a spare set, I have no use for them now, I guess it was at least a mopar guy who rigged up the down turn exhaust that was on there!